Ex-vivo rbc

Glycophorin A (GPA), a red blood cell (RBC) surface glycoprotein, can maintain peripheral blood leukocyte quiescence through interaction with a sialic acid-binding Ig-like lectin (Siglec-9). Under inflammatory conditions such as sickle cell disease (SCD), RBCs' GPA undergo structural changes affecting this interaction. Peripheral blood samples from SCD patients pre- and post-RBC transfusion were probed for neutrophil and monocyte activation markers and analyzed by FACS; RBCs were purified and tested by FACS for Siglec-9 binding and GPA expression, and incubated ex vivo with cultured endothelial cells to evaluate their effect on barrier function...

Renal ex-vivo normothermic machine perfusion (NMP) is under development as an assessment tool for high-risk kidney grafts, and as a means of achieving more physiologically accurate organ preservation. On-going hemolysis has been reported during NMP, as this technique relies on red blood cells (RBCs) for oxygen delivery. In this study we confirm the occurrence of progressive hemolysis during 6-hour kidney NMP. NMP-associated erythrostasis in the glomeruli and in peri-glomerular vascular networks point to an interaction between the RBCs and the graft...

OBJECTIVE: Histotripsy is a focused ultrasound therapy that ablates tissue via the action of bubble clouds. It is under investigation to treat a number of ailments, including renal tumors. Ultrasound imaging is used to monitor histotripsy, though there remains a lack of definitive imaging metrics to confirm successful treatment outcomes. In this study, a convolutional neural network (CNN) was developed to segment ablation on ultrasound images. METHODS: A transfer learning approach was used to replace classification layers of the residual network ResNet-18...

In contrast to red blood cells, platelets float rather than sediment when a column of blood is placed in the gravitational field. By the analogy of erythrocyte sedimentation (ESR), it can be expressed with the platelet antisedimentation rate (PAR), which quantitates the difference in platelet count between the upper and lower halves of the blood column after 1 h of 1 g sedimentation. Venous blood samples from 21 healthy subjects were analyzed for PAR. After a 1-h sedimentation, the upper and lower fractions of blood samples were analyzed for platelet count, mean platelet volume (MPV), immature platelet fraction (IPF), and high-fluorescence IPF (H-IPF)...

BACKGROUND: Decreased efficacy of artemisinin-based combination therapy (ACT) for Plasmodium falciparum malaria has been previously reported in patients with sickle cell disease (SCD). The main purpose of this study was to investigate the in vitro susceptibility of isolates to dihydro-artemisinin (DHA) to provide a hypothesis to explain this treatment failure. METHODS: Isolates were collected from patients attending health centres in Abidjan with uncomplicated P...

BACKGROUND: Blood clots are primarily composed of red blood cells (RBCs), platelets/thrombocytes, and fibrin. Despite the similarities observed between mammals and zebrafish, the composition of fish thrombi is not as well known. OBJECTIVE: To analyze the formation of zebrafish blood clots ex vivo and arterial and venous thrombi in vivo. METHODS: Transgenic zebrafish lines and laser-mediated endothelial injury were used to determine the relative ratio of RBCs and thrombocytes in clots...

The volume of oxygen drawn from systemic capillaries down a partial pressure gradient is determined by the oxygen content of red blood cells (RBCs) and their oxygen-unloading kinetics, although the latter is assumed to be rapid and, therefore, not a meaningful factor. Under this paradigm, oxygen transfer to tissues is perfusion-limited. Consequently, clinical treatments to optimize oxygen delivery aim at improving blood flow and arterial oxygen content, rather than RBC oxygen-handling. Whilst the oxygen-carrying capacity of blood is increased with transfusion, previous studies have shown that stored blood undergoes kinetic attrition of oxygen release, which may compromise overall oxygen delivery to tissues, i...

BACKGROUND: Autologous blood transfusion is one of the illicit strategies, banned by the World Anti-Doping Agency, to increase the levels of hemoglobin, with a consequent improvement in the delivery of oxygen to tissues. At present, this practice is detectable exclusively by the individual, longitudinal monitoring of hematological biomarkers, as in the hematological module of the Athlete Biological Passport; but this indirect approach may suffer from different confounding factors. We are presenting a multi-parametric, analytical strategy to detect autologous blood transfusions by targeting the modification of the red blood cells during storage...

Arachidonic acid 15-lipoxygenases (ALOX15) play a role in mammalian erythropoiesis but they have also been implicated in inflammatory processes. Seven intact Alox genes have been detected in the mouse reference genome and the mouse Alox15 gene is structurally similar to the orthologous genes of other mammals. However, mouse and human ALOX15 orthologs have different functional characteristics. Human ALOX15 converts C20 polyenoic fatty acids like arachidonic acid mainly to the n-6 hydroperoxide. In contrast, the n-9 hydroperoxide is the major oxygenation product formed by mouse Alox15...

This study aimed to deliver a potential water-soluble antiviral drug (sofosbuvir) through optimized vesicular lipid nanocarriers (LNs) to the rat brain as a novel strategy against viral meningitis. A 23 factorial design approach was established to assess the effect of formulation composition and process variables on the physicochemical properties of the LNs. Sofosbuvir-loaded LNs (SLNs) were developed by lipid layer hydration method utilizing optimized parameters and evaluated for various in vitro characterizations like FTIR, DSC, XRD, FESEM, vesicle size, zeta potential, drug carrying capacity and drug release...

BACKGROUND: Cerebral microhemorrhages (CMH) are associated with stroke, cognitive decline, and normal aging. Our previous study shows that the interaction between oxidatively stressed red blood cells (RBC) and cerebral endothelium may underlie CMH development. However, the real-time examination of altered RBC-brain endothelial interactions in vivo, and their relationship with clearance of stalled RBC, microglial responses, and CMH development, has not been reported. METHODS: RBC were oxidatively stressed using tert-butylhydroperoxide (t-BHP), fluorescently labeled and injected into adult Tie2-GFP mice...

BACKGROUND: Ultrafiltration (UF) is an extracorporeal technique for treating fluid overload and is monitored with noninvasive blood volume monitors. HYPOTHESIS/OBJECTIVES: The primary objective was to determine the accuracy of Crit-Line® III and IV noninvasive blood volume monitors to estimate canine packed cell volume (PCV) and changes in blood volume during UF. A secondary aim was to determine accuracy of targeted ultrafiltration rates (UFR) compared to calculated delivered UFR...

Normothermic machine perfusion (NMP) has reshaped organ preservation in recent years. In this preclinical study, prolonged normothermic perfusions of discarded human kidney grafts were performed in order to investigate perfusion dynamics and identify potential quality and assessment indicators. Five human discarded kidney grafts were perfused normothermically (37°C) for 48 h using the Kidney Assist device with a red-blood-cell based perfusate with urine recirculation. Perfusion dynamics, perfusate and urine composition as well as injury markers were measured and analyzed...

BACKGROUND: Thrombocytopenia has been consistently described in patients with extracorporeal membrane oxygenation (ECMO) and associated with poor outcome. However, the prevalence and underlying mechanisms remain largely unknown, and a device-related role of ECMO in thrombocytopenia has been hypothesized. This study aims to investigate the mechanisms underlying thrombocytopenia in ECMO patients. METHODS: In a prospective cohort of 107 ECMO patients, we investigated platelet count, functions, and glycoprotein shedding...

The malaria parasite Plasmodium falciparum invades and replicates asexually within human erythrocytes. CD44 expressed on erythrocytes was previously identified as an important host factor for P. falciparum infection through a forward genetic screen, but little is known about its regulation or function in these cells, nor how it may be utilized by the parasite. We found that CD44 can be efficiently deleted from primary human hematopoietic stem cells using CRISPR/Cas9 genome editing, and that the efficiency of ex-vivo erythropoiesis to enucleated cultured red blood cells (cRBCs) is not impacted by lack of CD44...

The cluster of differentiation 38 (CD38) is a well validated target for treating multiple myeloma (MM). Although anti-CD38 monoclonal antibodies have demonstrated outstanding initial responses in patients with multiple myeloma, nearly all patients eventually develop resistance and relapse. In addition, currently approved CD38 targeting therapies have failed to show monotherapy efficacy in lymphomas, where CD38 expression is present but at lower levels. To effectively target CD38 on tumor cells, we generated an ADCC enhanced bispecific CD38 x ICAM-1 antibody, VP301...

Cobalt intoxication can occur after its release from metal-based prostheses, which is generally clinically severe. Therefore, there is a need for the development of a cobalt chelator since there are currently no approved drugs for cobalt intoxication. As flavonoids are known for their metal chelating properties and safety, the screening of cobalt chelating properties was performed in a total of 23 flavonoids by our recently developed new spectrophotometric assay. Further assessment of positive or negative consequences of cobalt chelation was performed both in vitro and ex vivo ...

Synthesis of the acetylcholinesterase inhibitor paraoxon (POX) as a carbon-11 positron emission tomography tracer ([11 C]POX) and profiling in live rats is reported. Naïve rats intravenously injected with [11 C]POX showed a rapid decrease in parent tracer to ~ 1% with an increase in radiolabeled serum proteins to 87%, and red blood cells (RBCs) to 9%. Protein and RBC leveled over 60 min reflecting covalent modification of proteins by [11 C]POX. Ex vivo biodistribution and imaging profiles in naïve rats had the highest radioactivity levels in lung followed by heart and kidney, and brain and liver the lowest...

En bloc resection of bladder tumor (ERBT) is a promising alternative for non-muscle-invasive bladder cancer management. However, the tumor characteristics and surgeon's experience influence its application. Therefore, in this pilot study, we developed a technique called "rotatable bi-channel en bloc resection of bladder tumor (RBC-ERBT)" and assessed its feasibility, efficacy, and safety compared with those of conventional ERBT. In an ex vivo porcine bladder model, 160 bladder lesions of varying morphologies (exophytic and flat) and sizes (1 and 2 cm) were created and evenly distributed across different locations...

Beta-thalassemia and sickle cell disease (SCD) are autosomal recessive disorders of red blood cells due to mutations in the adult ß-globin gene, with a worldwide diffusion. The severe forms of hemoglobinopathies are fatal if untreated, and allogeneic bone marrow transplantation can be offered to a limited proportion of patients. The unmet clinical need and the disease incidence have promoted the development of new genetic therapies based on the engineering of autologous hematopoietic stem cells. Here, the steps of ex vivo gene therapy development are reviewed along with results from clinical trials and recent new approaches employing cutting edge gene editing tools...